io9: life on other planets

Jupiter's Moon Could Sustain Animal-Like Life

Lauren Davis — Fri, 09 Oct 2009 11:42:08 PDT

Water on out moon might make lunar colonization possible, but it appears that Jupiter's satellite Europa is better suited for life. A new study suggests Europa could support not just microorganisms, but complex life — and a lot of it.

Richard Greenberg of the University of Arizona will be presenting his findings on Europa today at American Astronomical Society's Division for Planetary Sciences. Europa's ability to support macrofauna — more complex organisms like animals — hinges on how much oxygen is contained in the suspected ocean beneath the moon's icy surface.

Greenberg believes that energetic particles from the sun are able to reach Europa's subterranean ocean despite that layer of ice. Because the surface of Europa is relatively impact-free, the ice is believed to be relatively new, about 50 million years. Based on this, Greenberg sets forth the idea that Europa is being constantly resurfaced, possibly with fresh materials, thanks to oxidizers at the planet's surface. He also estimates that, if there were, say, fish on Europa, and those fish used the same amount of oxygen as Earth fish, the moon's ocean has enough oxygen to support 6.6 billion pounds of such macrofauna.

Of course, just because Europa might be able to sustain life doesn't mean we'll find life there. But this does present the possibility that other bodies produce enough oxygen to support complex biological processes.

Europa, Jupiter's Moon, Could Support Complex Life [Discovery]

A Second Earth in Our Solar System

Annalee Newitz — Mon, 18 Feb 2008 16:30:25 PST

Traveling to another Earth-like world just got a lot easier. It turns out that there may be many other dirt-and-water planets lurking at the edges of our solar system in places like the Oort Cloud. These planets, which could be roughly the size of our own, would contain all the elements we need for life. They're just sitting in a cold, dimly-lit part of the solar system, waiting to be defrosted and colonized. Yesterday, NASA scientists announced that this changes the prognosis for nearby livable planets.

NASA's Alan Stern said these planets are so far away from the sun that we haven't seen them yet:

Our old view, that the Solar System had nine planets will be supplanted by a view that there are hundreds if not thousands of planets in our Solar System. It could be that there are objects of Earth-mass in the Oort cloud (a band of debris surrounding our planetary system) but they would be frozen at these distances. They would look like a frozen Earth.

So all we need to do is haul one of those babies into our orbit, defrost it, and start populating. Earth 2, here I come!

Beyond our solar system, millions more Earth 2s await. University of Arizona astronomer Michael Meyer, co-author of a study about extrasolar dirt-and-water worlds, told reporters:

Our observations suggest that between 20% and 60% of Sun-like stars have evidence for the formation of rocky planets not unlike the processes we think led to planet Earth. That is very exciting.

Image from Guardian Unlimited.

Planet-hunters set for big bounty [BBC News]

Is There Life On Saturn's Moon?

charliejane — Tue, 18 Dec 2007 13:30:23 PST

Do these water jets come from an underground ocean orbiting Saturn? If so, it could nurture the only extraterrestrial life-forms in our solar system. But one scientist says that water is too pure to come from a buried ocean on Enceladus, one of Saturn's moons.

The water has none of the sodium which it would have after years of contact with rock, claims University of Colorado scientist Nick Schneider. But other scientists argue there might be sodium which Schneider's telescope analysis failed to detect. And even Schneider isn't claiming there's no ocean on Enceladus, just that the water jets don't come from it. NASA may have to mount a mission to find out for sure if the Saturn moon holds life forms. Image by NASA/JPL [BBC]